The role of interstitial (crowdion) mass-transfer for crack high-temperature healing under uniaxial loading

Abstract

Crack healing was experimentally studied in the samples of pure copper at the temperature T = 873 K (≈0.65 Tm) under conditions of uniaxial loading perpendicular to the crack bedding plane. Analysis of experimental results using the kinetic equation of the crack healing by the dislocation-diffusion mechanism has shown that under such conditions the healing process is controlled by diffusion dissolution of generated dislocation prismatic loops due both to their vacancy ″evaporation″ caused by the loop curvature and to absorption of interstitial atoms generated in the cross-points of dislocation lines. Under conditions of the described experiments, both possibilities have been shown to realize equally that substantially accelerates the crack healing process. The migration of interstitial atoms in crowdion configuration has been proved quite real.